Motor driven chiseling device

ABSTRACT

A motor driven chiseling device for making cuts and grooves in rocks and other hard surfaces by means of a tool having milling teeth. The device has at least one working rod which by means of a joint is mounted for pendulum movement and is also movable in the direction of its longitudinal axis while extending from the interior of the transmission housing to the outside thereof. The passage of the working rod through the transmission housing is sealed by the joint. That portion of the working rod which is located outside the transmission housing is adapted to support a chiseling tool, whereas that portion of the working rod which is located within the transmission housing is operatively connected to a transmission system inside the transmission housing so that the transmission system causes the working rod to carry out a pendulum movement and if desired also an axial movement.

United States Patent 1191 Neuenberg Sept. 24, 1974 1 MOTOR DRIVEN CHISELING DEVICE 22 Filed: Apr. 16,1973 21 Appl. No.2 351,786

[30] Foreign Application Priority Data [58] Field of Search 173/126, 122; 299/69, 70, 299/71, 72; 74/47, 48, 49, 5O

[56] References Cited UNITED STATES PATENTS 220,272 10/1879 Burry 74/47 1,672,885 6/1928 G01C1SChmidt 74 61 3,157,437 11/1964 Gonski 299/71 3,233,265 2/1966 118111116116". 74 47 3,269,197 8/1966 15116615 74 50 3,341,254 9 1967 Arndt 299 71 3,365,963 1/1968 Happe 74/47 Primary ExaminerSamuel Scott Assistant ExaminerWesley S. Ratliff, Jr. Attorney, Agent, or FirmWalter Becker [5 7] ABSTRACT A motor driven chiseling device for making cuts and grooves in rocks and other hard surfaces by means of a tool having milling teeth. The device has at least one working rod which by means of a joint is mounted for pendulum movement and is also movable in the direction of its longitudinal axis while extending from the interior of the transmission housing to the outside thereof. The passage of the working rod through the transmission housing is sealed by the joint. That portion of the working rod which is located outside the transmission housing is adapted to support a chiseling tool, whereas that portion of the working rod which is located within the transmission housing is operatively connected to a transmission system inside the transmission housing so that the transmission system causes the working rod to carry out a pendulum movement and if desired also an axial movement.

8 Claims, 10 Drawing Figures MOTOR DRIVEN CHISELING DEVICE The present invention relates to a motor driven chiseling device for making cuts or grooves in rocks or the like by means of a tool provided with milling teeth.

In order to combine the advantages of tools which respectively operate in a milling and beating manner with regard to the principal action thereof and in order to be able to perform for instance groove chiseling operations in masonry or in street pavements in a more precise manner and at a reduced time, a motor driven chiseling device has been developed and has been described in my US. Pat. No. 3,706,474 which includes a transmission operable to convert the rotary movement of the driving motor into a pendulum-like oscillating movement of the tool in a plane passing through the longitudinal axis of said tool. The said device furthermore comprises a striking mechanism adapted during the pendulum movement of the tool to exert upon the latter a plurality of strikes in the longitudinal direction of the tool.

It is an object of the present invention to further develop and improve a chiseling device of the above mentioned type so that the driving elements will not be exposed to soiling by the rock dust or the like and to the wear inherent thereto but can be lubricated in a proper manner.

It is a further object of this invention to provide a motor driven chiseling device as set forth in the preceding paragraph which will bring about a quieter operation of the chiseling device and will make it possible for the operator more conveniently to hold the chiseling device while the holding means for the tool will be more rugged and more resistant to stresses and rough handling.

These and other objects and advantages of the present invention will appear more clearly from the following specification in connection with the accompanying drawings, in which:

FIG. 1 illustrates a view and partly a section of a first embodiment of a chiseling device according to the invention.

FIG. 2 represents a section taken along the line [H] of FIG. 1.

FIGS. 3, 4 and 5 respectively illustrate a detail on a larger scale than that of FIGS. 1 and 2 and of somewhat different designs.

FIGS. 6 and 7 show a special design for the connection of the chiseling device with the tool.

FIGS. 8 and 9 respectively illustrate in longitudinal section and cross section a second embodiment of a chiseling device according to the invention.

FIG. 10 illustrates an example for using the chiseling device of FIGS. 8 and 9.

The chiseling device according to the present invention is characterized primarily in that it is equipped with a working rod which by means of a joint is mounted for pendulum movement and also is longitudinally movable and extends through said joint from the transmission housing in a sealed manner toward the outside, said joint tightly closing a passage of the transmission housing for the working rod. The motor driven chiseling device according to the invention is furthermore characterized in that the lever arm ofthe working rod is located outside the transmission housing and has its end provided with means for receiving a tool, while the lever arm which is located inside the transmission housing is coupled to the transmission of the device which brings about the pendulum movement of the working rod. By the above mentioned design, all driving elements are completely encased and sealed relative to the dust-creating surroundings and are located in a completely closed transmission housing so that the driving elements, as it is desirable, can rotate in an oilfilled transmission chamber. Inasmuch as the pendulum movement of the working rod is carried out only in one plane, it is possible to employ an ordinary radial bearing, for instance in the form of a cylindrical joint body which receives the working rod so that it can move longitudinally. Such radial bearing, however, is required for obtaining a proper seal of the passage for the working rod through the wall of the transmission housing against oil leakage, and a relatively expensive and difficult design or an oil resistance bellows or the like. Therefore, according to a further feature of the present invention, the joint is designed as a ball which is received by ajoint box or cap of the transmission housing and which seals the oil filled transmission housing chamber and through which the working rod is passed preferably with a cross sectionally cylindrical section. By such a joint, the oil-tight closure of the transmission housing chamber is simple and reliable.

A further feature of the invention consists in that the lever arm of the working rod, which lever arm is located within the transmission housing, is by means of a connecting rod connected to a crank arranged on a transmission shaft. This lever arm has a roller arranged on a transverse spar which roller is adapted to roll on a non-round disc arranged on the transmission shaft. This disc is adapted to impart upon the working rod a longitudinal movement which is superimposed upon the pendulum movement, the roller being pressed against the disc by means of a spring acting upon the working rod. The disc may entirely or partially have its circumference provided with impact cams which during the pendulum movement cause the working rod together with the tool thereon to carry out a vibrating longitudinal movement. The disc may furthermore be provided with different radii of curvature so that the tool during the forward pendulum movement of the working rod is moved onto the surface to be worked and during the return pendulum movement of the working rod is lifted off the surface to be worked. This design of the transmission driving the working rod has the advantage that it will operate with simple transmission elements so that it is relatively inexpensive and can be made rugged while the device furthermore runs extremely quietly and free from vibrations. A further advantage of this transmission design consists in that the device, in order to realize higher outputs at wide cuts for instance for street markings, can be designed in a simple manner and in duplicate with tools which carry out oppositely directed pendulum movements inasmuch as the transmission shaft can without difficulties have arranged thereon two cranks and two discs for the drive of two sets of working rods. More specifically, the working rod sets will be able to carry out opposite pendulum movements in opposite direction with regard to each other.

A further feature of the invention consists in that the end of the lever arm of the working rod, which end is located outside the transmission housing, is designed in the form of a slender cone upon which a detachable tool holder is slipped. That end of this tool holder which faces toward the transmission housing is provided with a thread for an adjusting nut by means of which it is possible to pull the working rod out of the transmission housing against the thrust of a spring acting thereupon, to such an extent that the roller of the transverse spar is lifted off the disc. By means of the adjusting nut, it is possible to change the device conveniently and easily from a milling and striking operation to a merely milling operation, and vice versa. The slender cone of the working rod, which cone engages a correspondingly conical sleeve-shaped part of the tool holder, connects the tool holder firmly to the working rod while the cone and the tool holder may be clamped together by a screw connection. Advantageously, the tool lwltlcr has itn rim pm'tinnn of that end thereof which is located on the side otthe tool provided with pivot or tooth-shaped protrusions and recesses engaged by correspondingly shaped rim portions of the tool. In this way, large engaging surfaces are created between the tool holder and the tool so that a rugged connection between these two parts will be realized.

Rcfcrring now to the drawings in detail, the chiseling device illustrated therein comprises a drive motor 1 which through a bevel gear transmission 2 drives a transmission shaft 3 one end of which is equipped with a crank pin 4. The crank pin 4 is connected to the upper end of a working rod 6 by means of a connecting rod 5. For purposes of compensating for the unbalance of the crank, the transmission shaft 3 is equipped with a disc 7. Mounted on the transmission shaft 3 is a nonround disc 8 the unbalance of which is compensated for by a part 9 arranged on the transmission shaft 3. The working rod 6 is formed by a two-arm lever which is journalled so as to be able to carry out a pendulum movement and a longitudinal movement. As joint for said working rod 6 there is provided a ball 10 which is journalled in a dust and oil-tight manner in a socket ll of the transmission housing 12. The working rod 6 extends from the transmission housing 12 outwardly through the ball 10 in which the working rod is journalled likewise in a dust and oil-tight manner while being able to carry out a longitudinal movement. The ball 10 thus closes the passage in the wall of the transmission housing for the working rod so that all transmission elements are arranged in a transmission housing which is completely closed relative to its surrounding and that all transmission elements can run in a oilfilled transmission chamber. The lever arm of the working rod 6, which lever arm is located outside the transmission housing 12, has connected thereto a tool 13 provided with milling teeth. That other lever arm of the working rod 6 which is located inside the transmission housing and which is engaged by the connecting rod 5 of the crank drive, has a transverse spar 14 which protrudes outwardly and is equipped with a roller 15. This roller is continuously urged against the circumference of disc 8 by means of a spring 16 which acts upon the working rod 6. By means of thecrank pin 4, the working rod 6 is caused to carry out a pendulum movement, during which the roller rolls on the circumference of the disc 8 which rotates in synchronism with the crank. This disc 8 may be so shaped and arranged that it imparts upon the working rod 6 a certain and desired longitudinal movement which is superimposed upon the pendulum movement of the rod 6. With milling tools for harder substances which, as illustrated in FIG. 6 have pointed teeth and perform useful work in both directions of the pendulum movement, the disc may, in conformity with FIG. 3 over its entire circumference be provided with striking cams 17 or the like which impart upon the working rod 6 during its forward and return pendulum movement a vibrating longitudinal movement. With a milling tool provided with the customary inclined teeth as illustrated in FIG. I, the disc 8 is expediently provided with striking cams 17 only on that circumferential portion on which the roller 15 will roll during the forward pendulum movement of the working rod 6. In this instance, the disc 8 is expediently so designed as illustrated in FIG. 5 that that circumferential portion of the disc on which the roller 15 rolls during the return pendulum movement of the working rod 6 him a smaller rudhm of curvature than that circumferential portion on which the roller rolls during the forward pendulum movement of the working rod. In this way, the milling tool will during the return pendulum movement not only remain without striking effect but will also be easily lifted off from the working surface. A disc 8 according to FIG. 5 without striking cams, which only brings about that the milling tool by means of spring 16 is during the return stroke lifted off from the working surface, may be advantageous when employing the chiseling device in softer materials.

FIGS. 6 and 7 show a particularly advantageous and stable receiving and connecting device on the working rod 6 for the milling tool. The rod 6 has that end thereof which protrudes from the ball joint 10, 11 designed as a slender cone 18 having placed thereon a tool holder 19. By means of a nut 20, the tool holder 19 is clamped and secured to the cone 18. A pin 21 of the working rod 6 secures the tool holder 19 additionally against rotation on the cone 18. This slender cone connection between the working rod 6 and the tool holder is very stable and reliable. That end 22 of the tool holder 19 which faces the ball joint 10, 11 is provided with a thread and carries an adjusting nut 23. When the adjusting nut 23 occupies the position shown in FIGS. 6 and 7, the milling tool 24 operates with a beat because the spring 16 is able to press the roller 15 against the disc 8. When the adjusting nut 23 is screwed upwardly toward the ball 10 of the ball joint, the working rod 6 pulls out of the transmission housing against the thrust of spring 16 until the roller 15 is lifted off from disc 8. Subsequently, the tool 24 merely carries out a milling operation. By means of the adjusting nut 23, it is thus possible to eliminate the additional beating effect of the transmission in a quick and simple manner. That end of the tool holder 19 which is located at the side of the tool is provided with protrusions 25 and recesses 26, respectively, at the front and rear marginal area when looking in the direction of the pendulum movement. The said protrusions 25 and recesses 26 are adapted to be engaged by correspondingly fork-shaped disengaged marginal areas of the milling tool. As will be seen from FIG. 6, the tool thus extends around the tool holder at both sides in a somewhat U-shaped manner whereby for the transfer of the driving force of the working rod 6 carrying out a pendulum movement, large engaging surfaces are created for the milling tool. By means of screws 27, the milling tool is held in firm engagement with and on the tool holder 19.

As will be seen for instance from FIG. 7, a plurality of milling blades may be employed in bundled condition and may be driven together by the working rod of the chiseling device. FIGS. 8 and 9 illustrate an embodiment of the chiseling device according to the invention for still greater output requirements and very wide cuts as they are needed for instance for street guiding lines or the like. The transmission shaft 28 of this embodiment is designed as a crankshaft with no cranks 29 by which through connecting rods 30 two working rod sets 31 are driven. Furthermore, two nonround discs 32 provided with beating cams are mounted on the transmission shaft 28. The unbalance of these discs 32 is compensated for by discs 33 which, similar to the embodiment of FIGS. 1 and 2, act as beating bodies and respectively impart a vibrating longitudinal movement during the pendulum movement upon a set of working rods through the intervention of the transverse spar 34 and roller 35.

In view of the wide design of the two milling tool holders 36 to each of which there is connected a plurality of milling teeth 37, expediently with each working rod set, two or more working rods 38 are employed by means of which the tool holders 36 are connected while traverses 39 are interposed therebetween. The passage of the individual working rods 38 through the common transmission housing 40 is also in this instance effected by a ball joint 41 which sealingly closes the passage for said rods. In the illustrated double design of the device according to the invention, the set of working rods are expediently driven in such a way that they carry out pendulum movements in opposite direction with regard to each other.

FIGS. 8 and 9 furthermore illustrate an embodiment which has no drive motor of its own but is provided or driven by an outside motor for instance for employment on a tractor as illustrated in FIG. 10. The transmission shaft is passed on both sides out of the transmission housing 40 (FIG. 8) and is so designed for instance as multi-key shaft, that it is adapted to be coupled to a non-illustrated drive shaft of the tractor. The transmission housing 40 is on both sides equipped with bearings 42 by means of which it is connected to the tractor. During the milling operation, the transmission housing 40 is by a manually operable level through an elbow lever system 43 pressed downwardly and against the transmission box 44 of the tractor. For idling operation, the transmission housing 40 is by means of these levers pivoted upwardly in bearings 42 as indicated in FIG. in dot dash lines. For milling operations in street pavements, the device according to the invention is superior over heretofore known street milling machines in that it need not rely on a considerable warming up of the pavement by gas or infra-red radiation. This heating up of the street pavement as it is necessary with heretofore known machines of the type involved, limits the output of such machines. By employing the device according to the invention with a milling and striking operation, a heating of the pavement is either not necessary at all or only a slight heating is all that is required.

It is, of course, to be understood that the present invention is, by no means, limited to the specific showing in the drawings but also comprises any modifications within the scope of the appended claims.

What I claim is:

l. A motor driven chiseling device for producing cuts and grooves in rocks and other hard surfaces by means of a tool having teeth, which includes: housing means, transmission means arranged within said housing means and adapted to be motor driven from the outside of said housing means, an operating member extending from the outside of said housing means into the inside thereof and being operable by said transmission means to carry out a pendulum movement and to move in its longitudinal direction, and joint means journalled in said housing means and supporting said operating member where said operating member extends from the outside of said housing means into the inside thereof, that portion of said operating member which is located outside and housing means comprising means for receiving and holding a tool, said transmission means including: a transmission shaft having a crank operatively connected to that portion of said operating member which extends into said housing means, noncircular disc means connected to said transmission shaft for rotation therewith, roller means supported by said housing means, said roller means being operable to roll on the circumference of said disc means to impose an axial movement upon said operating member while the latter carries out a forward and backward pendulum movement, and spring means continuously urging said roller means against said disc means.

2. A device according to claim 1, in which that portion of said operating member which is located outside said housing means forms a relatively slender cone, and in which said means for receiving and holding a tool is formed by a detachable tool holder placed upon said cone and having that end portion thereof which is adjacent said joint means provided with a thread, said device also including adjustable nut means threadedly engaging said thread, and additional spring means continuously urging said operating member to farther move into said housing means, said adjustable nut means being operable to pull said operating member against the thrust of said additional spring means out of said housing means to such an extent that said roller means is lifted off from said disc means.

3. A device according to claim 2, in which that end portion of said operating member which is located outside said housing means is provided with protrusions and recesses for respectively engaging and receiving corresponding recesses and protrusions of a tool to be connected to said operating member.

4. A device according to claim 1, in which at least that circumferential portion of said disc means on which said roller means rolls when said operating member carries out a forward pendulum movement is provided with beating cams for imparting upon said operating member a vibrating movement in its axial direction.

5. A device according to claim 1, in which that circumferential portion of said disc means on which said roller means rolls during the backward pendulum movement of said operating member has a shorter radius of curvature than that circumferential portion of said disc means on which said roller means rolls during the forward pendulum movement of said operating member.

6. A device according to claim 1, in which said joint means includes socket means forming part of said housing means and also includes ball means journalled in said socket means and having a passage therethrough through which said operating member extends while simultaneously substantially oil tight sealing the interior of said housing means toward the outside.

7. A motor driven chiseling device for producing cuts and grooves in rocks and other hard surfaces by means of a tool having teeth, which includes: housing means, transmission means arranged within said housing means and adapted to be motor driven from the outside of said housing means, an operating member extending from the outside of said housing means into the inside thereof and being operable by said transmission means to carry out a pendulum movement and to move in its longitudinal direction, and joint means journalled in said housing means and supporting said operating member where said operating member extends from the outside of said housing means into the inside thereof, that portion of said operating member which is located outside said housing means comprising means for receiving and holding a tool, said transmission means including: a transmission shaft having two cranks, two noncircular disc means each peripherally provided with beating cam means, two sets of operating rod means respectively operatively connected to said cranks, and roller means respectively supported by said operating rods for respective rolling engagement with the respective pertaining disc means, said cranks being offset with regard to each other by so that said two sets of operating rods will carry out counter running pendulum movements when their roller means roll on the pertaining disc means.

8. A device according to claim 7, in which said joint means includes socket means forming part of said housing means and also includes ball means journalled in said socket means and having a passage therethrough through which said operating member extends while simultaneously substantially oil tight sealing the interior of said housing means toward the outside.

UNHED STATES PATENT OFFICE QETHEQATE 6F QGEC'UN Henry Neuenburg Inventor(s) ied that error appears in the above-identified patent It is certif and that said Letters Patent are hereby corrected as shown below:

"this embodiment is designed as a crankshaft with no" this embodiment is designed as a crankshaft with two Col. 5, line 5:

should read Signed and sealed this 17th day of December 197 4.

Commissioner of Patents Tic 0*!" HQ UIELBSON JR. C. MXRSHALL DANN ttesting Officer FORM PC4050 (10'69) USCOMM-DC 60376-PB9 U,S. GOVERNMENY PRIN ING OFFICE: 9 9 

1. A motor driven chiseling device for producing cuts and grooves in rocks and other hard surfaces by means of a tool having teeth, which includes: housing means, transmission means arranged within said housing means and adapted to be motor driven from the outside of said housing means, an operating member extending from the outside of said housing means into the inside thereof and being operable by said transmission means to carry out a pendulum movement and to move in its longitudinal direction, and joint means journalled in said housing means and supporting said operating member where said operating member extends from the outside of said housing means into the inside thereof, that portion of said operating member which is located outside and housing means comprising means for receiving and holding a tool, said transmission means including: a transmission shaft having a crank operatively connected to that portion of said operating member which extends into said housing means, noncircular disc means connected to said transmission shaft for rotation therewith, roller means supported by said housing means, said roller means being operable to roll on the circumference of said disc means to impose an axial movement upon said operating member while the latter carries out a forward and backward pendulum movement, and spring means continuously urging said roller means against said disc means.
 2. A device according to claim 1, in which that portion of said operating member which is located outside said housing means forms a relatively slender cone, and in which said means for receiving and holding a tool is formed by a detachable tool holder placed upon said cone and having that end portion thereof which is adjacent said joint means provided with a thread, said device also including adjustable nut means threadedly engaging said thread, and additional spring means continuously urging said operating member to farther move into said housing means, said adjustable nut means being operable to pull said operating member against the thrust of said additional spring means out of said housing means to such an extent that said roller means is lifted off from said disc means.
 3. A device according to claim 2, in which that end portion of said operating member which is located outside said housing means is provided with protrusions and recesses for respectively engaging and receiving corresponding recesses and protrusions of a tool to be connected to said operating member.
 4. A device according to claim 1, in which at least that circumferential portion of said disc means on which said roller means rolls when said operating member carries out a forward pendulum movement is provided with beating cams for imparting upon said operating member a vibrating movement in its axial direction.
 5. A device according to claim 1, in which that circumferential portion of said disc means on which said roller means rolls during the backward pendulum movement of said operating member has a shorter radius of curvature than that circumferential portion of said disc means on which said roller means rolls during the forward pendulum movement of said operating member.
 6. A device according to claim 1, in which said joint means includes socket means forming part of said housing means and also includes ball means journalled in said socket means and having a passage therethrough through which said operating member extends while simultaneously substantially oil tight sealing the interior of said housing means toward the outside.
 7. A motor driven chiseling device for producing cuts and grooves in rocks and other hard surfaces by means of a tool having teeth, which includes: housing means, transmission means arranged within said housing means and adapted to be motor driven from the outside of said housing means, an operating member extending from the outside of said housing means into the inside thereof and being operable by said transmission means to carry out a pendulum movement and to move in its longitudinal direction, and joint means journalled in said housing means and supporting said operating member where said operating member extends from the outside of said housing means into the inside thereof, that portion of said operating member which is located outside said housing means comprising means for receiving and holding a tool, said transmission means including: a transmission shaft having two cranks, two noncircular disc means each peripherally provided with beating cam means, two sets of operating rod means respectively operatively connected to said cranks, and roller means respectively supported by said operating rods for respective rolling engagement with the respective pertaining disc means, said cranks being offset with regard to each other by 180* so that said two sets of operating rods will carry out counter running pendulum movements when their roller means roll on the pertaining disc means.
 8. A device according to claim 7, in which said joint means includes socket means forming part of said housing means and also includes ball means journalled in said socket means and having a passage therethrough through which said operating member extends while simultaneously substantially oil tight sealing the interior of said housing means toward the outside. 